Support automake 1.14
Simplify ZeroTerminated
Remove GirFFI::Struct

All methods have been moved to StructBase
Remove nil check
Replace duplicate method with included module
Add descriptions for several modules
Make EnumBase a DataConverter

This removes the need for overriding FFI::Library#find_type.
Extract struct class creation method
Extract method klass in builders
Clean up use of BuilderHelper
Remove trailing whitespace
Move list constructor definition to ListMethods
Extract common method #index from Array and PtrArray
Use ContainerClassMethods in Array implementation
Use ContainerClassMethods in PtrArray implementation
Make element_type read-only for List and SList
Use 1.8.7-compatible way of getting the singleton class
Move SizedArray from GLib to GirFFI
Make SizedArray handle conversion of values to and from pointer
Use EnumBase as its own FFI type